Python Lists
Comprehensions, slicing, sorting, and friends for sequences.
- list comprehension
- python slice
- sorted key
- zip
- any all
Python Lists
Comprehensions, slicing, sorting, and friends for sequences.
Commands
| Command | What it does |
|---|---|
[x*x for x in range(10)] | List comprehension |
nums[1:4] | Slice (start inclusive, end exclusive) |
sorted(users, key=lambda u: u.name) | Sort without mutating |
zip(names, scores) | Pair two sequences |
any(x > 0 for x in nums) | Existence check, short-circuits |
Example
scores = [("ada", 95), ("grace", 88)]
top = sorted(scores, key=lambda s: s[1], reverse=True)
print([name for name, _ in top])FAQ
list vs tuple?
Lists mutate (append/sort); tuples are fixed and hashable — use tuples for dict keys and records.
Why is my default-arg list shared?
Mutable default args persist across calls; use None and build inside the function.
よくある質問
list vs tuple?
Lists mutate (append/sort); tuples are fixed and hashable — use tuples for dict keys and records.
Why is my default-arg list shared?
Mutable default args persist across calls; use None and build inside the function.
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